Trailer for road vehicles



Jan. 26,1937.

M. R. BUTLER ET AL 2,069,004

'TRAILER FOR ROAD VEHICLES Oi'iginal Filed July 13, 19:55

Patented Jan. 26, 1937 UNITED STATES PATENT OFFICE TRAILER FOR ROADVEHICLES Original application July 18, 1935, Serial No. 32,080. Dividedand this application February 3, 1936, Serial No. 62,182. In New ZealandAugust 10, 1934 5 Claims.

This application is a division of our application Serial No. 32,080filed July 18, 1935, and the invention relates to trailers for roadvehicles.

The object of the present invention is to enable the trailer to besupported by the drawing vehicle but to have free horizontal andvertical movement in relation thereto.

According to the present invention, a trailer coupling is providedconsisting of a transverse draw bar pivoted at its centre to a framefixed to the vehicle. The ends of this draw bar are guided in membersfixed on the end of the frame and are pivoted to the trailer body andsupport the trailer laterally, provision being made to permit the crossbar to assume the necessary transverse angle when rounding a curve andalso of any accentuated angle, such as when the vehicle is travellingaround a corner where one side of the road is higher than the other.

The invention will be described with the aid of the accompanyingdrawing, wherein:-

Figure 1 is an elevation showing a trailer attached to a vehicle.

Figure 2 is a plan of a trailer but not showing the floor or sides,these being of approved form.

Figure 3 is a cross section on line 33 Figure 2, but drawn to a largerscale than the preceding views.

Figure 4 is an enlarged plan of the portion shown in Figure 3.

Figure 5 is a cross section on the line 55 of Fig. 4 showing thepivoting of the cross bar to the trailer frame.

Figure 6 is a cross section on the line 6-6 of Fig. 2 showing how theunder carriage is connected to the frame of the trailer by means of aspring.

Referring to the drawing, the coupling for the trailer consists of atransverse trailer draw bar I pivoted at its center on a pin 2 carriedby a member 3a of a frame which also includes bars 3 and end Plates 4,the parts 3, 3a and 4 being attached to each other by welding. The endplates 4 are bolted to a convenient part of the rear of the vehiclechassis, or to brackets attached to the rear thereof, according to thetype of vehicle to which it is applied. The end plates 4 are arcuate,and have fixed to their upper edges by welding, arcuate guide membersIa, while complementary arcuate guide members I are fixed thereto bystuds 8a, the members Ia being cut away so as to leave slots 6 betweeneach two members. The ends of the draw bar I slide in the slots 6, whichlatter extend in their arcuate form a distance which permits the bar Ito rotate on the pivot 2 and enables the trailer to follow the drawingvehicle during any turnin movement of such vehicle.

These arcuate guide members in a rearward direction slope upwards fromthe horizontal, as indicated in Figure 3, so that when the draw bar Irotates on its ivot 2, a tilting action is obtained which will permitthe bar I to take the required transverse angle in relation to theframe. The bearing for the bar I about the pivot 2 is disposed at thesame inclination as the slots 6. The bar I has downwardly projectingends Ia pivoted by means of pins 8 (Figure 5) to the side members 9 ofthe trailer frame in order to allow the necessary flexibility betweenthe trailed and the drawing vehicle.

At a convenient point near the rear of the trailer, a trailed wheel I2is mounted by means of suitable bearings I3 carried by members I4depending from a transverse wheel frame I5 which carries a spring I6.The ends of the spring pass through slots Ila of brackets I'I fixed tothe side members 9 of the body of. the trailer. A block i8 fixed on theside of each bracket Il may slide against the depending end I5a of theframe I5. These blocks act as lateral guides.

The front end of the frame I5 extends forwardly and is pivoted at II! toa transverse member 29 of the body of the trailer frame so that verticalmovement of the rear end of the frame can take place.

This arrangement of. a central wheel, together with the use of the drawbar I, having its ends free to move in the sloping guide slots 6, enablethe frame of the trailer to assume the transverse plane of the drawingvehicle when rounding a curve, and also any accentuated angle, such aswhen the vehicle is travelling around a curve where one side of the roadis higher than the other.

The guides I and la retain the trailer in an upright position, while thedraw bar I being pivoted at its center, allows the horizontal turningmovement to take place between the trailer and the vehicle, while theprovision of the axis at 8 allows for free movement of the trailer aboutsuch axis.

What we claim is:-

1. A trailer for vehicles comprising a coupling pivoted centrally tosaid frame and having the r by the provision of a single road wheelcarried by and supporting said trailer frame.

5. A trailer as claimed in claim 1 characterized by the provision of awheel frame movably carried by the transverse frame, a supporting wheelcarried by said wheel frame, and a spring interposed between the wheelframe and the trailer frame.

MARTIN RONALD BUTLER. WIILIAM HENRY HARDING.

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